1. A cut-off in the TeV gamma-ray spectrum of the SNR Cassiopeia A
- Author
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G. Pedaletti, E. Prandini, Stefano Ansoldi, Riccardo Paoletti, Wolfgang Rhode, A. De Angelis, A. Treves, Vitaly Neustroev, T. Surić, M. I. Martínez, Juan Abel Barrio, M. Engelkemeier, B. De Lotto, S. Bonnefoy, Sabrina Einecke, L. Maraschi, Kazuma Ishio, Elina Lindfors, G. Maneva, J. Kushida, Razmik Mirzoyan, U. Barres de Almeida, Damir Lelas, Rodolfo Carosi, Daniel Mazin, A. Berti, Wlodek Bednarek, Alessandro Carosi, Jose Luis Contreras, Adrian Biland, Chiara Righi, Dorota Sobczyńska, M. Colak, N. Torres-Albà, J. Palacio, M. Hayashida, J. Rico, Camilla Maggio, J. M. Paredes, Antonio Stamerra, B. Banerjee, Daniela Dorner, C. Arcaro, Dariusz Gora, Juan Cortina, Gaia Vanzo, D. Zarić, Arka Chatterjee, S. Schroeder, Marc Ribó, Stefano Covino, Ivica Puljak, Pierre Colin, M. Gaug, Pratik Majumdar, L. Nogués, D. Fidalgo, P. Bangale, M. V. Fonseca, Abelardo Moralejo, E. Moretti, Hidetoshi Kubo, Tomohiro Inada, L. A. Antonelli, J. Herrera, S. N. Shore, E. de Oña Wilhelmi, Martin Will, Petar Temnikov, Koji Noda, Tomoki Saito, D. Tescaro, Marcel Strzys, Elisa Bernardini, Masahiro Teshima, Yusuke Konno, P. G. Prada Moroni, Kyoshi Nishijima, Nikola Godinovic, D. Ninci, D. Kuveždić, Tomislav Terzić, Ievgen Vovk, M. Minev, Tarek M. Hassan, T. Schweizer, I. Reichardt, Fabrizio Tavecchio, A. Niedzwiecki, Ll. Font, I. Snidaric, U. Menzel, M. Peresano, David Paneque, Max Ludwig Ahnen, P. Giammaria, D. Guberman, Marina Manganaro, Ana Babić, D. Galindo, M. Garczarczyk, P. Cumani, Konstancja Satalecka, Michele Doro, Francesco Dazzi, Dario Hrupec, A. Fernández-Barral, M. A. Lopez, R. J. García López, Kari Nilsson, Massimo Persic, F. Di Pierro, D. Dominis Prester, V. Fallah Ramazani, P. Da Vela, Alexander Hahn, Julian Sitarek, J. Hose, M. Vazquez Acosta, B. Biasuzzi, Victoria Moreno, E. Colombo, L. O. Takalo, Aaron Dominguez, D. Hadasch, Francesco Longo, J. E. Ward, Mosè Mariotti, Saverio Lombardi, Martin Makariev, Oscar Blanch, M. Doert, J. R. Garcia, J. Becerra González, Christian Fruck, L. Perri, Giacomo Bonnoli, Wrijupan Bhattacharyya, D. Eisenacher Glawion, D. Elsaesser, M. Nievas Rosillo, S. Paiano, Karl Mannheim, Ahnen, M. L., Ansoldi, S., Antonelli, L. A., Arcaro, C., Babić, A., Banerjee, B., Bangale, P., Barres de Almeida, U., Barrio, J. A., Becerra González, J., Bednarek, W., Bernardini, E., Berti, A., Bhattacharyya, W., Biasuzzi, B., Biland, A., Blanch, O., Bonnefoy, S., Bonnoli, G., Carosi, R., Carosi, A., Chatterjee, A., Colak, M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., de Oña Wilhelmi, E., Di Pierro, F., Doert, M., Domínguez, A., Dominis Prester, D., Dorner, D., Doro, M., Einecke, S., Eisenacher Glawion, D., Elsaesser, D., Engelkemeier, M., Fallah Ramazani, V., Fernández-Barral, A., Fidalgo, D., Fonseca, M. V., Font, L., Fruck, C., Galindo, D., García López, R. J., Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Gora, D., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Hayashida, M., Herrera, J., Hose, J., Hrupec, D., Inada, T., Ishio, K., Konno, Y., Kubo, H., Kushida, J., Kuveždić, D., Lelas, D., Lindfors, E., Lombardi, S., Longo, F., López, M., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menzel, U., Minev, M., Mirzoyan, R., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Nievas Rosillo, M., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peresano, M., Perri, L., Persic, M., Prada Moroni, P. G., Prandini, E., Puljak, I., Garcia, J. R., Reichardt, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Saito, T., Satalecka, K., Schroeder, S., Schweizer, T., Shore, S. N., Sitarek, J., Šnidarić, I., Sobczynska, D., Stamerra, A., Strzys, M., Surić, T., Takalo, L., Tavecchio, F., Temnikov, P., Terzić, T., Tescaro, D., Teshima, M., Torres-Albà, N., Treves, A., Vanzo, G., Vazquez Acosta, M., Vovk, I., Ward, J. E., Will, M., and Zarić, D.
- Subjects
lepton ,Astrophysics ,power spectrum ,01 natural sciences ,Spectral line ,Astrophysics::Solar and Stellar Astrophysics ,MAGIC (telescope) ,010303 astronomy & astrophysics ,acceleration of particle ,cosmic ray ,energy spectrum [gamma ray] ,acceleration of particles ,ISM: supernova remnants ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Spectral index ,education.field_of_study ,Gamma ray ,cosmic rays ,gamma rays: general ,high [energy] ,Spectral energy distribution ,Electrónica ,Física nuclear ,Electricidad ,Astrophysics - High Energy Astrophysical Phenomena ,Astrophysics::High Energy Astrophysical Phenomena ,low [magnetic field] ,Population ,energy spectrum ,FOS: Physical sciences ,Cosmic ray ,Astrophysics::Cosmology and Extragalactic Astrophysics ,GLAST ,leptonic [model] ,emission [gamma ray] ,supernova ,0103 physical sciences ,education ,Astrophysics::Galaxy Astrophysics ,Computer Science::Information Theory ,ta115 ,010308 nuclear & particles physics ,Astronomy ,cosmic ray physics ,stars: supernovae: individual: Cassiopeia A ,supernova remnants ,Astronomy and Astrophysics ,acceleration ,MAGIC ,moment ,flux ,Cassiopeia A ,Space and Planetary Science ,ddc:520 ,galaxy [cosmic radiation] ,spectral ,High Energy Physics::Experiment ,supernova remnant [ISM] ,general [gamma rays] - Abstract
It is widely believed that the bulk of the Galactic cosmic rays are accelerated in supernova remnants (SNRs). However, no observational evidence of the presence of particles of PeV energies in SNRs has yet been found. The young historical SNR Cassiopeia A (Cas A) appears as one of the best candidates to study acceleration processes. Between December 2014 and October 2016 we observed Cas A with the MAGIC telescopes, accumulating 158 hours of good-quality data. We derived the spectrum of the source from 100 GeV to 10 TeV. We also analysed $\sim$8 years of $Fermi$-LAT to obtain the spectral shape between 60 MeV and 500 GeV. The spectra measured by the LAT and MAGIC telescopes are compatible within the errors and show a clear turn off (4.6 $\sigma$) at the highest energies, which can be described with an exponential cut-off at $E_c = 3.5\left(^{+1.6}_{-1.0}\right)_{\textit{stat}} \left(^{+0.8}_{-0.9}\right)_{\textit{sys}}$ TeV. The gamma-ray emission from 60 MeV to 10 TeV can be attributed to a population of high-energy protons with spectral index $\sim$2.2 and energy cut-off at $\sim$10 TeV. This result indicates that Cas A is not contributing to the high energy ($\sim$PeV) cosmic-ray sea in a significant manner at the present moment. A one-zone leptonic model fails to reproduce by itself the multi-wavelength spectral energy distribution. Besides, if a non-negligible fraction of the flux seen by MAGIC is produced by leptons, the radiation should be emitted in a region with a low magnetic field (B$\lessapprox$100$\mu$G) like in the reverse shock.), Comment: 8 pages, 3 figures, submitted to MNRAS. Corresponding authors: Daniel Guberman (dguberman@ifae.es), Emma de O\~na Wilhelmi (wilhelmi@ice.csic.es) and Daniel Galindo (dgalindo@am.ub.es)
- Published
- 2017
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